Certain integrated circuit (IC) packages or modules include semiconductor devices, such as chips or dies, contained in an encapsulating material or housing. The IC package or module includes an exterior array of contacts, or input/output pads, for electrically connecting the package or module to another electronic component, such as a load board adapted for use with a package testing system. The contacts of an IC package typically are not connected directly to the load board. Typically, an interconnect assembly (e.g., a test socket) is interposed between the IC package and the load board to provide electrical connection between the contact array of the IC package and a contact array of the load board.
Referring to FIG. 1, there is shown a prior interconnect assembly 100 located between an IC package 102 and a load board 104 adapted for use with a package testing system. The IC package 102 includes an array of electrical contacts 108 located on an exterior surface of the package. The exemplary array of contacts 108 is of a type known as a “land grid array” in which the contacts 108 have substantially planar contact surfaces. The load board 104 also includes an array of electrical contacts 110.
The interconnect assembly 100 includes a plurality of conductors 112 received in openings 116 defined by a support frame or carrier 114. As shown, the openings 116 of the carrier 114 are spaced to provide for substantial alignment between the conductors 112 and the contacts 108, 110 of the package 102 and the load board 104, respectively. Each of the conductors 112 is compressible to provide a variable length for the conductor 112. Such adjustable conductor length allows the interconnect assembly 100 to accommodate dimensional variations, amongst the contacts 108, 110 for example. Such dimensional variation results in variation in the separating distance between pairs of contacts 108, 110 when the package 102 and the load board 104 are brought into contact with the interconnect assembly 100 as shown in FIG. 1. The adjustable length for the conductors 112 ensures that each of the conductors 112 of the interconnect assembly 100 will contact the package 102 and the load board 104.
Each conductor 112 of the interconnect assembly 100 includes plunger members 118, 120 defining opposite ends of the conductor and a cylindrical barrel 122 located between the plunger members 118, 120. A coil spring or other resilient member (not shown) is coupled between the plunger members 118, 120 and contained within the barrel 122. Compression of the coil spring under loading placed on the plunger members 118, 120 results in the desired shortening of the distance between opposite ends of the conductor 112. This type of conductor having elongated plungers, a barrel and a coil spring is sometimes referred to as a “spring pin” or “pogo pin.”
The carrier 114 of the prior interconnect assembly 100 includes a socket portion 124 and a retainer portion 126 secured together by fasteners at locations 128. The carrier 114 of prior interconnect assembly 100 can be secured to the load board 104 by fasteners at locations 130. Each of the carrier portions 124, 126 defines an annular shoulder 132 adjacent the openings 116 for retaining the barrels 122 of the conductors 112 within the openings 116. As illustrated in FIG. 1, the barrel 122 of each conductor 112 is dimensioned to define a gap between the conductor 112 and the annular shoulders 132. This gap provides vertical play between the carrier 114 and the barrels 122 of conductors 112.
Referring to FIG. 2, the interconnect assembly 100 of FIG. 1 is located between a load board 104 and an IC package 134. Instead of including a land grid array of contacts like package 102, package 134 includes an array of contacts 138 having a rounded configuration. This type of contact array is sometimes referred to as a “ball grid array.”